30 NEW YORK STATE MUSEUM 



ASBESTOS 



The minerals which supply the asbestos of commerce are known 

 to occur in several places within the State, more especially in the 

 crystalline areas of the Adirondacks and southeastern New York. 

 They are nowhere mined at present, but the occurrences have been 

 at different times the object of inquiry and more or less attention 

 which in one instance has extended to considerable exploratory work. 

 The purpose of this article is to mention the different localities which 

 have come to light and to give whatever information is available 

 concerning their features and possible importance. 



That the local occurrences have aroused some interest from a 

 commercial standpoint is not surprising in view of the recent great 

 development in the uses of asbestos and of the remarkable growth 

 of the Canadian mining industry which supplies the larger share 

 of the world's needs of the material. The principal mines of Canada 

 are situated in the province of Quebec, on the south side of the 

 St Lawrence river, not very remote from the northern boundary of 

 New York. The district in fact extends southward across the 

 Vermont line, in which State there are similar occurrences which 

 have more or less importance. 



The proximity of the Adirondack crystalline region to that district 

 might be regarded as favorable to its carrying the same kind of 

 deposits, but there is really no basis for such inference as a little 

 consideration will show. The asbestos of Canada and Vermont is 

 found within a belt of metamorphosed Paleozoic formations which 

 lie along the flanks of the Green Mountain uplift. The particular 

 home of the mineral is in serpentine, in this case the product of 

 alteration of old igneous rocks originally composed of minerals of 

 the olivine and pyroxene groups. A large nimiber of serpentine 

 bodies are known in the stretch from southern Vermont into and 

 across the eastern townships of Quebec, but in only a few is asbestos 

 present in workable proportions. The mines or quarries are based 

 on masses of serpentine that carry closely crowded veinlets of 

 chrysotile, the latter occurring in such profusion as to permit the 

 excavation of the whole mass, from which the fiber is then obtained 

 by hand picking or by milling operations. 



No similar bodies of serpentine are found in the Adirondacks. 

 The latest igneous intrusions in that region took place before the 

 opening of the Cambrian period, and the sedimentary formations were 

 laid down at a much earlier date. The igneous intrusions did not 

 include any rocks of the peridotite class (composed of olivine) and 

 consequently there has been no material from which large serpentine 



